Impacts of warming and water deficit on antioxidant responses in Panicum maximum Jacq

Abstract

Agricultural activities are affected by many biotic and abiotic stresses associated with global climate change. Predicting the response of plants to abiotic stress under future climate scenarios requires an understanding of plant biochemical performance in simulated stress conditions. In this study, the antioxidant response of Panicum maximum Jacq. cv. Mombaça exposed to warming (+2°C above ambient temperature) (eT), water deficit (wS) and the combination eT + wS was analysed under field conditions using a temperature free‐air‐controlled enhancement facility. Warming was applied during the entire growth period. Data were collected at 13, 19 and 37 days after the start of the water deficit treatment (DAT) and at two sampling times (6:00 and 12:00 h). A significant decrease in chlorophyll was observed under the wS treatment, but an increment in total chlorophyll was observed in eT + wS, particularly at 19 DAT. Significant increase in H2O2 content, malondialdehyde and protein oxidation was observed in the wS treatment at noon of the third sampling. In the combined wS + eT stress treatment, the activity of the enzymatic antioxidant system increased, particularly of superoxide dismutase (SOD; EC 1.15.1.1) and ascorbate peroxidase (APX; EC 1.11.1.11). The chlorophyll fluorescence images showed that the photochemical performance was not significantly affected by the treatments. In conclusion, under simulated future warming and water stress conditions, the photosystem II (PSII) activity of P. maximum acclimated to moderate warming and a water‐stressed environment associated with a relatively favourable antioxidant response, particularly in the activity of APX and SOD.

Nitrate reductase is required for salicylic acid‐induced water stress tolerance of pepper by upraising the AsA‐GSH pathway and glyoxalase system

“…The MDA (lipid peroxidation) and H 2 O 2 are well‐known indicators of oxidative impairment, which were both found to be higher under WS in this experiment, relevant to WW‐plants, indicating higher oxidative impairment in plants under WS. It has similarly been observed that WS‐induced oxidative stress, indicating higher MDA and H 2 O 2 by Borjas‐Ventura et al (2019) and Zhang et al (2019b). Furthermore, under WS condition, electrolyte leakage was higher due to higher MDA and H 2 O 2 as reported previously in durum wheat by Slama et al (2018).…”

Fungal communities differentially respond to warming and drought in tropical grassland soil

“…Previous experiments carried out by our research group at the Trop-T-FACE facility have shown the impacts of warming and water deficit on field-grown C4 and C3 forage plant species (Borjas-Ventura, Alves, de Oliveira, Martínez, & Gratão, 2019;Habermann, Dias de Oliveira, Contin, Delvecchio, et al, 2019;Habermann, Dias de Oliveira, Contin, San Martin, et al, 2019;Viciedo, Prado, Martínez, Habermann, & Piccolo, 2019). Here, we reported changes in the soil fungal communities due to the isolated and combined effects of soil water deficit and a 2°C increase in canopy temperature.…”

Elevated CO2 and warming change the nutrient status and use efficiency of Panicum maximum Jacq

“…C 4 species are adapted to warm, as well as arid environments. Experiments suggest that Panicum maximum (Guinea grass) would benefit by a 2˚C warming under well-watered conditions by exhibiting increased dry mass [11] and not showing increased concentration of stress indicators compounds, such as malondialdehyde and hydrogen peroxide [12]. However, under heating, there was no increase in photosynthesis and transpiration [6,13], suggesting that under a warmed atmosphere, P. maximum may exhibit increased NUE.…”